Patent document 1: Patent Publication of Japanese Patent No. 3543652
In a rack-and-pinion type steering apparatus, a rack shaft having rack teeth meshing with the teeth of a pinion is movably supported through a bush bearing by a gear box serving as a housing. As bush bearings, synthetic resin-made bush bearings have been variously proposed, and such a synthetic resin-made bush bearing is generally adapted to movably support the rack shaft with an interference.